Certain characteristics of the accumulation of Paleozoic,Mesozoic, and Cenozoic sediments in Ustyurt

Interpretation of the regional litho-stratigraphic section (fig.) leads to identifications of several meso-rhythms within the three macrorhythms of the sedimentation, the corresponding marine transgression-stability - regression sequences, and their paleoclimatic connotations. As the result, the source rock series are tentatively identified as the Lower-Middle Jurassic and the Apt-Albian sediments, the transgressive complexes, and this conclusion is sustained by indications of hydrocarbons in both. – V.P. Sokoloff.